Patients who have experienced impact, twist or other damage, or who have undergone serious surgery of the back, e.g., of the lumbar region, particularly of the spine, are typically required, or at least advised, to essentially immobilize the back by maintaining a prone position for extended periods of time. In many cases however it has been recognized that some, even though slight motion of the damaged and/or adjacent areas of the back during recovery or rehabilitation has beneficial effects, for example, in enhancing blood flow to the area, in helping to maintain muscle strength and tone, and in maintaining a general feeling of activity and well-being in the patient.